This invention concerns the removable connection of two elements in general, and in particular the removable connection in fixed rotational and longitudinal relationship of two tubular elements.
The need to selectively connect and disconnect tubular members or hose-like members can arise in many environments. One common circumstance in which the general public is faced with such connection/disconnection problems is with modular, telescopically-related members comprising a collection of attachments for a vacuum device. For example, a typical canister-style vacuum cleaner may have two or more tube or hose sections and related attachments which the user may selectively configure for desired use, and which may be disconnected for storage. In such instance, it is desirable to provide interconnecting members which are reliably air-tight to prevent loss of vacuum power, but preferably without requiring specialized tools or training for either connection or disconnection of the members.
Another desirable aspect of modular attachments for vacuum systems, from the perspective of the user, is that individual damaged pieces may be replaced as needed without the expense of replacing the entire set of attachments. Heretofore, relatively longer hose pieces (often corrugated or the like for added strength) have been one of the more costly components of a set, and have required a significant member integrally formed therewith or permanently attached thereto for operatively engaging the hose with a piece of vacuum equipment.
Various tubular coupling arrangements related to suction cleaning devices are known in the prior art. Some of these are commonly referred to as detent-type connectors, by virtue of their having a resilientlybiased member selectively positioned for coupling and uncoupling. For example, Martinet (U.S. Pat. No. 2,582,446), Coss (U.S. Pat. No. 2,420,866), and White (U.S. Pat. No. 2,212,679), all disclose air-tight tubular couplings wherein one tubular member is received inside another and variously secured thereto by a resilientlybiased member. In each such patent, the outer tubular member is provided with some type of opening through its circumference, while the inner tubular member has an outwardly biased projection for engaging such opening to secure the tubular members together. The outward biasing for the projections may be selectively overcome by the user with various tools or direct actuation elements as disclosed by the references so as to permit disconnection of the two tubular elements.
Other types of connecting devices are also known. For example, Helm et al. (U.S. Pat. No. 3,212,795) disclose inwardly tapering grooves on the inside diameter of a receiving member for guiding coupling bosses formed on the outside of two-segment hinged coupling member which surrounds an end of a hose. The bosses are guided towards boss-engaging openings formed in the circumference of the receiving member, and located longitudinally beyond the end of the grooves and in line with the respective longitudinal axes thereof. Various tools may be used to force the bosses inward and thus out of engagement with the openings therefor, which permits withdrawal of the hose and its surrounding coupling member from the receiving member.
Symes et al. (U.S. Pat. No. 343,089) disclose two members adapted for telescopic coupling, with slots or openings defined in the outside member for receipt of lugs outwardly mounted on the inside member. Once such lugs are positioned in the slots, a collar about the outside member is rotated so that inwardly projecting lugs of such collar engage the lugs of the telescopically-received inside member for securing the coupling.
In still another known tubular coupling construction, Martinet (U.S. Pat. No. 2,245,151) provides a slot located partially about the circumference of a receiving member for retaining an outwardly biased boss of a received member. Such structure is intended to permit relative rotation of the coupled elements during use thereof. However, the amount of such rotation is limited by opposite circumferentially spaced ends of such circumferential slot which cause disengagement of the coupled tubes. As noted in Martinet's own later patent (U.S. Pat. No. 2,582,446; listed above), such twistable coupling of his '151 patent frequently becomes accidentally disconnected so that positive connection is thus not reliably assured at all times.